The present invention relates generally to tissue graft materials, and in particular aspects to tissue graft constructs including a submucosa or other extracellular matrix material having exogenous growth factors bound thereto. Such materials are useful in wound care, such as in the treatment of chronic wounds, e.g. chronic ulcers.
As further background, wound healing is a complex process involving platelets, the immune system, the extracellular matrix, and various cytokines and growth factors. Wound healing generally occurs in four major phases: inflammation, cell proliferation, matrix deposition, and remodeling. Each stage of healing requires a specific group of extracellular signals to proceed. These extracellular signals can include the presence of growth factors and cytokines, whose order of release and concentrations are controlled during the healing response by cells in the wound. The type of growth factors and cytokines that participate in wound healing can vary depending on the species of the patient, the type of wound, and the wound's location.
Dermal wound healing is especially critical to maintaining the body's primary line of defense. The skin provides the body with a protective barrier from chemical and mechanical challenges, harmful pathogens, and ultraviolet radiation. Chronic wounds compromise the skin's ability to defend against these agents, due to the prolonged wound healing process.
For chronic wounds, the body is unable to complete the wound healing process due to compromised vascularization or immune system. Without clinical intervention, these chronic wounds can lead to the spread of infection, significant necrotic tissue, and possible amputation in the case of ulcers in the foot. Advanced states of chronic dermal wounds present a significant clinical challenge. In the United States alone, there are over 3 million cases of chronic wounds annually.
In view of this background, there remain needs for improved or alternative medical grafting materials, methods for manufacturing medical grafting materials, and methods for using medical grafting materials. The present invention is addressed to these needs.